Centralization versus decentralization of information systems : a critical survey and an annotated bibliography

Center

Systems

Research

Massachusetts Institute ofTechnology

AlfredP, SloanSchoolof Management

50 Memorial Drive

Cambridge, Massachusetts, 02139

CENTRALIZATION VERSUS DECENTRAJ.IZATION

OF INFORMATION SYSTEMS:

A

M

by

Jacob Akoka

November 1977

CISR #36

Sloan WP #1003-78

updated annotated bibliography

by Christine Bullen

Introduction

The literature dealing with the issues related to distributed

manage-ment information systems is rapidly expanding. This literature may be

classified in two categories:

• the management-oriented literature which is concerned

with the issue of centrali;;ation versus decentralization

of information systems and the management of distributed

processing;

a the technically-oriented literature which deals with issues

such as optimizing distributed networks and currency

con-trol in computer networks.

This survey deals only with the first aspect of distributed systems.

In the first part of this paper, a critical study of the state of

the art in distributed management information systems is provided. In

the second part, an annotated bibliography related to the issue of

cen-tralization versus decentralization of information systems is presented.

This bibliography updates the one published by the Center for Information

Systems Research (CISR) (1976) (1)

.

(1) Rockarc, J.I', and Leventer, J.S., "Centralization versus

Decentraliza-tion of Information Systems: An Annotated Bibliography, CISR Report 22,

April 1976

-2-I. CENTRALIZATION VERSUS DECE^^'RAL_IZATION OF INFORMA.TION SYSTEMS:

A

The issue of centralization versus decentralization of computer

re-sources is not a new one; it has been widely discussed and hotly debated for

at least two decades now. The interest in this issue was originally motivated by

the feeling that the computer, a costly expense in terr.s of investment and

operat-ing budget, should be used to the fullest possible potential. Interest also grew

because it was felt that within a corporation, a large measure of political

power rested with whomever controlled the data processing facility. Lately

advances in network technology and the advent of efficient low cost mini and

micro computers has initiated the era of distributed data processing and in

effect thrown new fuel into the centralization/decentralization fire.

Of the voluminous literature published on this subject, we first concentrate

on key articles relating to one aspect of the problem: the

centralization/de-centralization decision. Management, faced with decisions regarding proper

long range directions toward optimal configurations of hardware, software, and

personnel finds little by way of guidelines to follow. There seems then to be

a real need for a rigorous decision model to provide management with an

approach to solving this dilemma.

Ernest Dale (2) states: "the proper balance between centralization and

decentralization often is decided by necessity, intuition, and luck because of

the immense variety of possible human behavior and vast multiplicity of

minute, undiscoverable causes and effects that cannot be encompassed in

(2) Dale, E. '"Centralization versus Decentralization," Advanced Management,

- 3

-any principal or standard of evaluation." In addition, current solutions seem

highly dependent on the characteristics, philosophies, and objectives of

the particular organization for which the decision is to be inade. Accord-ing to George Glaser (3) , "the organizational approach to data p'-ocessing

should be consistent with the overall* organizational approach of the

com-pany in which it functions." The problem is not only of major importance

but of substantial complexity also.

Having surveyed many articles available in the literature it is clear

that, with few exceptions, most articles fit one of the following categories:

• a general discussion of advantages and disadvantages of various configurations as viewed from a decision-making perspective;

• the establishment of decision criteria from specific

cor-porate functions;

• a proposed decision model by which management can m.ake

qualitative decisions about organizational directions

based on specific data processing applications;

« a discussion of distributed systems as being a new and

attractive approach to the

centralization/decentraliza-tion decision.

The first groun of articles is very general and focusses on discussions

of advantages and disadvantages of various ccif igurations. From a

func-tional point of view, cost applications could be accomplished by either

(3) Glaser, G., "The Centralization versus Decericralization Issue: Ar^^'inants

,

- A

-centralized or decentralized approaches. However, as G.A. Champ ine (4)

states, "each of the two approaches has advantages and disadvantages.

In general the advantages of a centralized approach are the disadvantages

of a distributed approach and vice versa." For example, some of the

ad-vantages and disadvantages he lists are:

"Centralized advantages/distributed disadvantages"

o Operations economy

• Hardware economy of scale

• Unified control

• Easy interfile communications

• Easy update/retrieval • Compatibility

"Distributed advantages/centralized disadvantages"

• Communication failsoft capability

• Central site failsoft capability

• Lower communication data rate and costs

• Configuration flexibility

• High speed performance (fast response and high

transaction rate)

• Modular upgrade

Dozens of authors have written similar articles citing specific adva-" j,-s

and disadvantages. Some of these articles ar^i described below:

Rejmolds (5), argues that three economic considerations have to

be taken into account: personnel to operate the hardware, data processing

(4) Champine, G.A., "Six Appraoches to Distributed Databases," Datamation,

May 1977

-5-applications progranming efforts and the conputing. All three considerations can lead to some economic saving when implemented in a centralized way.

Reynolds uses his own organization, Hughes Aircraft Corporation, as an

illustration of his argument.

Kieder (6) argues that two considerations are critical in arriving

at the most effective type of organization for a particular corporation -i.e. corporate structure itself (irrespective of data processing tasks

performed) and size and location of tKe corporation.

Wofsey's (7) article is mainly a discussion of the respective

ad-vantages and disadvantages of both the centralized and decentralized approaches to systems design.

Finally, Burnet and Nolan (8) argue that the technology has now

matured to the stage where the cost of using a mini for certain data

processing jobs compares favorably with using a portion of tlie capacity

of a large machine.

In some articles this approach takes a more general form. Louis

Fried (9) exemplifies this in his article when he states, "As part of

the continuing discussion that is almost as old as the computer industry,

there have,been as many reasons advanced for decentralization as for

centralization. However, in contrast to the arguments for centralization, which center around efficiency, the arguments for decentralization center

around effectiveness." It is my contention that this first group of articles ±s too geieral and diverse from which to draw -any meaningful generalizations

(6) Kieder, S.P., "Once again Centralize or Decentralize," Infosystems,

December 1976

(7) Wofsey, M.M. , "Centralization versus Decentralization," Manage-ent

of EDP Syste~.3 , 1973

(8) Burr.et, G.J., and Nolan, R.L., "At Last Major Roles for Minicomputers,"

Harvard Business Review, May-June 19/5

(9) Fried, L., "Centralization: To Be or Not To Be," Infosystems. January

- 6

-in terms of deoleions regarding optn.^1 solution. As Rockart -•

et. al. (10) state, "The articles on the advantages and disadvantages

of centralization and/or decentralization abound in the literature.

Since different authors have different assumptions and approach the

prob-lem somewhat differently, their arguments are not strictly comparable."

The second group of articles approaches the discussion of centralization

versus decentralization in terms of corporate functions. These articles

are far more useful in that they propose specific ways of looking at the

decision. Norton (11) reiterates this point by stating,

"Generaliza-tion is meaningless when applied as a generality to information systems.

Indeed, the concept of centralization must be approached in terms of

specific functions which make up operations and management of an

organiza--iion's information.system." Accordingly. Norton groups information systems

related activities into three categories: systems development, systems

operations, and systems management. Each of these categories can be

defined functionally as follows:

Systems Development: This includes system design, the development

of detailed specifications and programs, implementation plans, and maintenance

plans.

Systems Operations; This includes the editing and control of input

and output, updating data files, processing, and the reporting of results.

Systems Management; This includes planning long range directions

and projects, and maintaining control over the entire facility.

(10) Rockart, J.F., and Leventer, J.S., "Centralization versus

Decentral-ization of Information Systems: A Critical Survey of Current Literature," CISR Retport 23, April 1976

(11) Norton, D.?.,

"Inromaticn

-7-He then goes on to more rigorously define these activities and observes

that the administrative planning and control tasks undoubtedly have more influence on the effectiveness and efficiency of an information system

than other variables. Carl H. Reynolds (12) takes a similar approach

to that of Norton's. Ke divides data processing facilities into three

com-ponents: "the computing hardware," "personnel required to operate the

hard-ware," and "data processing applications programming efforts." These

categories less rigorously define the activities of a data processing facility

and are therefore less useful.

This approach, by which the problem is divided into smaller pieces,

leads to the third category which consists of only one article. Rockart

et. al. (13) follow Norton's reasoning that activities performed by information

systems are three distinct processes: systems operation, systems management,

and systems development. Since each is an independent process, the decision to centralize or decentralize can be made independently for each one. The

authors further segment the problem by looking at the decision in light of the

applications being performed. Their proposal is then basically that decisions to centralize or decentralize can be made separately for each of Norton's

processes (system development, system operations, and system management)

and each group of closely related applications of being performed. Rockart's

model does offer general guidelines for management to follow. It takes a

step in the right direction in that the model proposes concrete procedures

to follow. Although Rockart relies on mainly qualitative methods of

evaluation, his division of decisions with regard to applications opens

the door to quantitative evaluation methods. .

(12) Reynolds, C.H., op. cit.

(13) Rockart, J.F., Leventer, J.S., and Sullen, C.V., "Centralization

versus Decentralization of Information Systems: A Primary Model

- 8

-The last group of articles discusses distributed data processing as

a new and promising trend in data processing configuration, which could elimi-nate the whole centralization/decentralization problem, John Lusa (14) states,

"Some people are still arguing the comparative merits of centralizing or

decentralizing infosystems activities. While the discussion goes on at a

somewhat academic level, a relatively new phrase, if not necessarily

repre-senting a new concept, may keep the discussion at that level. Distributed

processing has blossomed into major prominence as a technique for

increas-ing the efficiency of a data processing operation to the benefit of the

users." This new trend brought on by network technology and the advent

of low-cost mini and micro computers has indeed created an appealing

al-ternative for certain situations. Other authors such as John W. Luke (15),

Richard G. Canning (16) and Tien Chi Chen (17) , to name a few, take similar

positions in favor of distributed data processing. Distributed processing

(14) Lusa, J. M. , "Distributed Computing Alive and Well", Infosystems_,

November 1976.

(15) Luke, J. W., "Unravelling the Confusion of Distributed DP",

Info-systems, December 1976.

(16) Canning, R. G. , "Is Your Future Distributed Systems?", EDP Analyzer_,

Vol. 11, No. 8, August 1973.

(17) Chen, C. T., "Distributed Intelligence for User Oriented Compull..o",

_ Q _

may well be the computing phenomenon of the 1980's, and it may well be

the solution to some problems. However, aini computers and network

technology will not solve all data processing problems. And the

funda-mental issue of which data and which coEputer processing should take

place at the outboard end of the systea (decentralized) and which

in-board (centralized) still remains.

In conclusion 1 would like to offer Robert L. Patrick's (18)

obser-vation, "A mini is a good solution, sometimes. Decentralization

—

distributed processing, or distributed computing, or whatever

—

good solution sometimes, but they are only good solutions to some problems,

As in most things we do, the important work is in deciding whether the

solutions we like fit the problems we have."

In surveying the literature, little was found in the way of hard conclusions. The centralization/decentralization decision process is

still very subjective at best. But the factors involved in making

cen-tralization/decentralization decisions are now coming more clearly into

focus.

(18) Patrick, R.L., "Centralizing Hardware and Dispersing Responsibility",

- 10

-II. CENTRALIZATION VERSUS DECENTRALIZATION OF INFORMATION SYSTEMS:

AN ANNOTATED BIBLIOGRAPHY

Becker,

Hal B.

"Preparing for Distributed Data Processing," DataComm User, January 1977, pp. 22-24

This article focuses on new network planning

phil-osophy. It begins by defining the inforcation

net-work environment, stating the user's requirements,

and then using a design sequence to identify

speci-fic hardware and software products. It's a

particu-larly useful technique for distributed processing

networks.

The author divides user requirements into three

basic categories:

1. information processing, or manipulation of Information in a way that produces the desired result;

2. netv7ork processing, or the movement of

information between the various network

nodes;

3. database or storage of information within

the network in forms convenient to network

users.

Becker,

Hal, B.

The author claims that the users requirements should

be essentially independent of specific hardware,

soft-ware and applications. These functional requirements

are defined in terms of: topology, anticipated volume

of information flow, existing information processing

facilities, response time, availability, and security.

Using the requirement statement as input, the analysis

and design sequence employs an iterative, interacti""

series of steps to derive a workable, optimum,

econom-ically justifiable network configuration.

"Six Steps to Network Analysis and Design," DataComm

User. March 1977, pp. 30-31

In this article, the author arguos that in the

str-Jt-tured approach to network inpiemsntation, tj.e analysis

£nd design sequence involves an iterative, interactive

series of steps. It is iterative in that some or all

- ₁₁ -Blair, James, F. Champlne, G.A. Donaldson, Hamish,

that it consists of a combination of automated algorithms

and manually derived design and decision making processes. The sequence consists of six basic steps: the

require-ment staterequire-ment, physical and logical design, performance

prediction, installation/operation, performance validation

and evolution.

"Distributed Inforiration Systems," Telecommunications,

January 1974, pp. 39-40

Distributed ii'.ronnatlon systems are defined here as a hierarchy of processors linked together, each of which may have human as well as database interfaces. A table

defines the typical characteristics of six types of

dis-tributed information systems, however, the distinction

among the types may blur in actual use. Two examples of

DIS are presented: a communication network for the Texas

Department of Public Safety, and one for Bancsystems Association

of Cleveland, a credit authorization organization. By

utilizing the concept of a hierarchy of processors for communications efficiency, many corporations and

institu-tions are achieving cost effective systens. This will

have an overwhelming impact upon the growing data

com-munications industry.

"Six Approaches to Distributed Data Base Systems,"

Datamation, May 1977

In this paper, it is argued that distributed databases

offer a solution to the very real problems of

geograph-ically distributed organizations which need to preserve

a unified information sharing and processing system.

Computer industry trends, such as falling costs of

pro-cessing and storage compared to more stable

coirjiiunica-tion costs, are responsible for the increasing appeal of

distributed database systems. The paper describes the two basic approaches to distributed databases which are

to replicate the database at each node, which will

work

commun-ication costs high; or to partition- the database, which

works best when most transactions are to "local" large

files. It is shown that when most transactions are not

to local files and file size is large, centralization of

some form may still be the economically justified answer.

"A Case for Distributed Processing," Data Exchange,

July-August ,1975, pp. 43-45

It is argued here that decentralized management needs

- ₁₂

-have different needs, b) it requries a very strong

manager to impose the sane system en two different

divisions, c) a changing business strategy requires

flexibility. The author suggest one should develop

common systems only where there is a very clear common

need.

Edited

Regarding management, however, what seems to be

re-quired is, according to the author, a sort of dual

management: business management from the user

manage-ment and technical supervision from management services

(i.e. DP). It is claimed that in small to medium sized

companies central control is essential. In larger

organizations more flexibility is possible and the advantages of centralized control must be weighed against potential dangers of over-bureaucratic

inter-ference. In summary, central control of systems

development is usually desirable.

"Distributed Data Systems," EDP Analyzer, Vol. 14,

June 1976, pp. 1-13

In this paper, it is claimed that one of the problems

with distributed systems is deciding what functions

should be distributed, where they should be distributed,

how to control the operation of the hierarchy of

func-tions, and how to insure database integrity. Some

mo-tivations for distributed systems are: 1) to enhance

reliability, 2) to take advantage of falling processing

costs, 3) to handle growing transaction volume, 4) to

perform input validation on the spot. In this paper,

it is argued that there are three main ways of

partition-ing systems:

1. Partitioning Of An Application System. Here the

system designer must search for the natural clus-tering of activities.

2. Partitioning, By Functional Area. Each department

would probably have its Cati minicomputer system,

and the several departmental systems might be tied

together in some sort of network system.

Edited

3. Partitioning Of The Data Processing Function.

Sup-porting remote data entry, handling data

communica-tions functions, or handling the database management.

"Distributed Systems and the End User," EDP Analyzer,

Vol. 14, No. 10, October 1976

The article focuses on the numerous reasons which account

- 13

-Edited

example, one reason is the reduction in overall

op-erating costs that these systens promise. Another

reason is that they give each organizational unit the

resources to do its own data processing - _{to "control}

its own destiny" in the words of one executive. At

the same time distributed systems may well bring

radi-cal change in the whole data processing environment,

as we know it today. Almost all aspects of the data

processing function - systems development, programming,

data entry, and computer operations - may shift in the

direction of the end user. This article includes the experiences of some organizations where such a shift

has already started.

"Distributed Computing and the Mini-Computer," Canadian Data Systems , July 1974, pp. 38-39

This article claims that distributed computing means

putting the computer power where the job is. The

author asserts that by using the right small computer

at the right place, there are increases of control and

a reduction of communications costs. It is argued

that, only summary data needs to be communicated to other

elements in an overall system. This article further

lists areas around a plant where computer power should

be distributed.

Edited "Distributed Minis Score Over One Large System at Equitable," DataComm User, March 1975, pp. 51-52

In this paper, it is reported that the Equitable Life

Insurance Society has implemented a series of

distribut-ed mini computer systems in aspects of its claims

pro-cessing, and statistical analysis. It is argued that

the mini's shorter implementation period, low

implemen-tation cost compared to large batch/on line computer

systems, lower operating costs, and lower site

prepar-ation costs are factors which lead to the decision.

Equitable uses the mini's for processing in real-time

mode for the following applications: group claim payment

r.ys-tem; calculations for group insurance compensations for

agents; administration of medicare for the states of

Idaho, New Mexico, Tennessee, and W^/oming; integrnted

group insurance system, to miintain a unified dat^:! base

with exhaustive premium and claim information for all

policies; and a satellite programming office in Cresskill,

- 14

-Edited : "Talking About Distributed Processing," Data Systems

,

February 1976, pp. 8-23

This article presents a number of different views on

both the principle and practice of distributed

pro-cessing. At the present time, distributed processing

systems are evolving rather than being planned. It

is argued that dispersed unconnected data processing

systems are turned into distributed systems by the

in-stallation of ccmmunication links. Such systems have

evolved throui^L the need to retain vital data

locally, and to improve the operation and control of.

remote systems. Problems connected with the concept

are largely management oriented. The editor stresses

the fact that the planning phase is vitally important

and must be exhaustive and informed. Management must

also solve the problem of security and lack of

uniform-ity of accounting techniques.

Edited : "Talking About Networks," Data Systems, March 1977,

pp. 7-9

Thi§ article indicates that there are now more than

twelve major communication networks, private and

commercial in the world. It is claimed that the implementation of a network raises many problems

be-yond those of its design. The article describes below

some of these problems:

1. Standardization And S:.E:3le Interfaces To All Kinds Of Hardware And To Other :.'etvorks. The

Interna-tional Standards Organization has been largely

con-cerned with this and was responsible for high level

data link control. The issue has been complicated

by IBM's introduction of systems network

archi-tecture.

2. Tariffs. Agreement must be reached between

coun-tries involved in networks which cross national

boundaries. The difficulties' of privacy and data

security increase costs.

3. Demands Of Individual Government Authorities,

Particularly In The Case Of Security And P-^ivacy

On International Networks. The author describes

- 15

-Edited : "Distributed Processing Is In, V;hatever It Is," Datamation,

Vol. 22, December 1976, pp. 102-111

The article recognizes the fact that distributed

proces-sing appears tobe flourishing in Europe. Most plans will

be implemented In the next 3-4 years. Most are planning

to put part of their databases and processing capability

into intelligent terminal systems, microconputers, and

small business systems located at user departments

or remote factory floors, distribution centers, and sales

offices. Reasons tended to center on better services

to end users, followed by cost implications.

It is claimed that the central site generally remains in

ultimate control. Hardware selection and systems program-ming will be done by a central staff. Standardization is

the reason for centralized control. Applications include

order processing and inventor;/ or stock control,

produc-tion control and planning, and local management and

fin-ancial applications. Most remote processors will have a

portion of the database and will be in daily communication

with the host processor.

Emery, : "Managerial and Economic Issues in Distributed

James C. Computing," IFIP Proceedings. 1977, pp. 945-55.

"Discusses technological developments which have„jnade

it feasible to distribute processing functions,

alter-native computing configurations, and the centralization versus decentralization issue. The advantages and

hazards of distributed systems are also examined."

[from Quarterly Bibliography of Computers and Data

Processing, Vol.7, no. 4, January 1978.]

Fledelman, ; "It's A Small World," Infosystems, Vol. 24, April 1977,

Lawrence pp. 50-54

In this article, the author argues that the distributed

system using minicomputers is not the only means to meet

the needs for multi-locaticn data processing; in fact,

it Is in direct compt>.j.i.j.ci with large computer systems

with on-line remote terminrls. However, as the price of

minicomputers continues to drop, extensive business soft-ware enhancements are introduced, data communications

facilities become more economical> «nd the data processing

manager develops more knowledge of how to handle this

sit-uation, we are seeing an ever growing trend toward

dis-tributed crr-utin^. The ccta prtce^sins m-ir.a'.;er vill reed

to determine how such equipment can best be utilized ana

- 16

-Fried, Louis

"Centralization: 1976

To Be or Not To Be," Infcsystems, January

Glaser, George Hannan, James and Fried, Louis Hunter, John J.

This article begins with the description of

Citibank's data processing reorganization toward

decen-tralization. It is claimed that change can be traumatic

and the "average" corporation is advised to avoid it

un-less it is well justified. Arguments are presented citing

advantages and disadvantages on both sides of the

central-ization/decentralization issue. The best structure^in

the end, seems to result from careful analysis of the

total corporate requirements of data

processing. After the many considerations are weighed ,

the best reorganization method should be tailored to fit

an individual corporate situation.

"Distributed Data Processing: Promises and Pitfalls," Proceedings of the IDC Conference on Distributed Data Processing, April 1977

George Glaser begins this article by refering to

dis-tributed data processing as "offering the joys of

computerdom long promised by the industry. As with any

reorganization plan the costs are likely to be high,

but he cites this as similar to the costs of any

tech-nological advance. The author claims that the primary advantage

of

im-prove the quality of service rendered by an enterprise,

in that operating needs would be assessed more

real-istically and on a more timely basis. This is not to

say reorganization toward distributed processing is not

without problems. The author asserts that a battery of

issues like spending authorities, development priorities,

quality control, and standards will certainly challenge even the most experienced managers' skills.

"Should You Decentralize," Computer Decisions, Vol. 9,

February 1977, pp. 40-42

This article approaches the question of centralization

versus decentralization from an advantages versus

dis-advantages perspective. Several systems incorporating

the best of both are discussed, and specific criteria

is outlined for making the decision.

"Distributing a Database," Computer Decisions, Vol. 8,

June 1976, pp. 36-40

The author reports that about a decade ago, there was a

switch from remote processing to a new discipline of

cen-tralized commuting. Some problems that came with

cen-tralization were enormous databases, data inavailability

due to line failures, concern for data security,

:_--overloading of the central processor. One answer to these

concerns proposed by D? strategists is distributed

17 -Kelsch, August L. Kleder, Stephen P. La Vole, Paul

points where the transactions occur. This way the user's

data are always available, and there is no worry about

data cocmunications failures.

Possible ways of distributing a database to meet the

de-mands of the three cost coinaonly used distributed

pro-cessing networks - _{star, hierarchal} and ring - are also also discussed.

"Dispersed and Distributed Data Processing," Journal

of Systems Manager.ent, Vol. 29, No. 3, March 1978,

pp. 32-37.

This article focussfes on an organizational design which

"marries" distributed and centralized data processing

In an attempt to "maximize the availability of the

com-puter as a business service tool." The author allocates

operational responsibility to the end user of a

distrib-uted system and retains technical responsibilities in a

centralized DP group.

"Once Again: Centralize or Decentralize", Infosystems,

December 1976.

This article addresses the issue of centralization vs.

decentralization of corporate data processing systems. The article cites two considerations as critical in

arriving at the most effeccive type of organization

for a particular corporation: 1) corporate structure

itself Irrespective of data processing tasks performed; and

2) size and location. The author finishes by citing

several advantages are disadvantages for both systems.

"Distributed Computing, Systematically", Computer

De-cisions. Vol. 9, March 1977, pp. 44-45.

It Is argued that a system approach is mandatory In the

field of distributed data entry and processing. The

author claims that this new field promises important

benefits both to the DP manager and to the user departments.

The author argued that since distributed data entry and processing is a new technique, there are few

stan-dards and even fewer general systems design principles.

This article contains some basic questions

which should help DP management avoid some of these pitfalls.

Luke,

John W,

"Unravelling the Confusion of Distributed Data Process-ing", Infosystems, December 1976.

Tlie author claims that there is considerable divergence

of views on the definition of distributed processing. As a

consequence, it rii-cS the question of vhcthir di-tributei

- 18

-. It is claimed that network services are already

provid-ing distributed processing. Integration of an on-site machine into a network enables utilization of

all the systems resources while retaining control over

the local installation. However, there are still

soft-ware problems to be solved before the full potentialities

of such integration can be realized.

It is argued that commercial networks have a formidable

arsenal of advantages which are offered to their customers.

Re-liability is one of the most valuable features as well as

hundreds of application packages. Thus the author claims

networks offer the best of both centralized and

decentral-ized worlds

.

Lusa, : "Distributed Computing: Alive and Well", Infosystems,

John M. November 1976.

This article suggest that distributed computing is blossoming into a technique of major importance for

increasing the efficiency of data processing

opera-tions. "Distributed Data Processing might be

des-cribed as the marriage of minis and telecoms:unications",

and will mature into the electronic office of the

future.

Patrick, : "Decentralizing Hardware and Dispersing Responsibility",

Robert L. Datamation, May 19 76.

This article states that at one time Grosch's law was more

nearly correct. It may still be useful today when applied to the CPU cluster alone, but support costs,

which are primarily personnel costs, rise more slowly

than the costs of the computer configuration and

there-fore continue the argument that bigger is cheaper.

On the opposing side, the complexity of the entire

sys-tem of hardware, software, and personnel, rises much

more rapidly than computer power or costs. Wnen that

complexity rises to a point where it taxes our abilities

to manage, it argues strongly against centralization

in-spite of any economies of scale.

As a conclusion the author claims: "A mini is a good solu-tion, sometimes. Decentralization or distributed

pro-cessing or distributed computing or whatever -- is a good

solution sometimes, but they are only good solutions to

some problems. As in most things we do, the important

work is in deciding whether the solutions we like fit

- ₁₉

-Re>molds,

Carl H.

"Issues in Centralization", Datamation, March 1977.

This article addresses Hughes Aircraft Company's

de-cision to'centralize their data processing functions.

By doing so it v/as estimated that data processing

costs could be cut by a factor of two.

The article centers on three economic considerations fundamental to making any

centralization/decentraliza-tion decision.

First is the personnel to operate the hardware. Usually centralization offers some savings however as on-line processing comes into greater use, the operator ex-pense will be less an issue. Also the ease with which multiple tasks can be performed by operators at

small-er decentralized installations tends to lessen this expense.

The second issue to be considered is data processing

appli-cations programming efforts. Here one should e>?pect savings

from centralization only if there exists in a

corpora-tion common programming applications. In corporations

with varied application of data processing facilities decentralization can be more economical.

The last issue to be considered is the computing hardware.

Economy of scale does not seem to be as important an

argu-ment for centralizaton as it used to be due to the advent

of inexpensive mini-computers: Tracking down system

failures in smaller decentralized installations is easier

and can in fact mean additional savings in data

proces-sing costs.

Ritchie,

Robert 0.

It appears that the centallzation resulted in major

cost savings for Hughes Aircraft Company in data

processing functions. Some effectiveness might have

been sacrificed but in terms of the individual data

processing needs of the company, centralization was

detejcmined to be the better organizational structure.

"Intelligent Terminals and Distributed Processing",

Computer Decisions, February 1975, pp. 36-42.

In this paper it is argued that intelligent terminals

and distributed processii»g provide processing

capa-bilities to remote locations, freeing the large cen-tral computer of menial processing tasks.

Communica-tion costs decrease, fewer I/O's are needed to the data

base or mainframe, and the user has computational power

unique to his requirements as well as a much more

re-liable system and independence from error-prone

communi-cations f'ciiitias. The Euthor gives su~:;e3tion? to

- 20 -Rockart, John F. and Leventer, Joav S. and Bullen, Christine

"Centralization versus Decentralization of Infornation

Systems: A Preliminary Model for Decision-Making",

CISR Report, Sloan School of Management, MIT, Cambridge,

Massachusetts (forthcoming).

Of the many organizational decisions facing management

today one of the most difficult must certainly be wtiether

to centralize or decentralize their data processing

structure. In this area v/here guidelines are general

at best, Rockart proposes a model which if used

proper-ly assesses each pertinent factor involved in a

corpora-tion and logr.cally determines which functions within the

data processiiig facility should be done locally and

which functions should best be accomplished centrally. Thus the model is based on Norton's observation that the activities performed by information systems are in

fact three distinct processes: systems development,

systems operation, and systems management. Since each

of these is an independent process the decision to

cen-tralize or decentralize can be made independently for

each process. Further segmentation with respect to

logical application groups can be made for both systems

development and systems operations, however systems

management is viewed as being a decision made for the corporation-as a whole.

Rockart's decision model though entirely qualitative

offers precise guidelines for m.anagement to follow.

It is the most advanced model in this area.

Severino,

Elizabeth F.

"Databases and Distributed Processing", Computer Decisions,

Vol. 9, March 1977, pp. 40-42.

It is argued here that the concepts of distributed

pro-cessing are maturing. This growth should play a role in

the

sys-tem. There are two kinds of processing power,

horizon-tal and hierarchical. In horizontal distribution, all

de-vices co-operate at the same logical level to perform

a set of tasks. Rule and control are democratic. The

processes exchange jobs or transactions so that the total

workload is distributed. In a hierarchical scheme of

distribution, the devices are interconnected to form a

functional hierarchy. The sharing of tasks and other

functional relationships are structured and all devices are

controlled by a primary network computer. There are also hybr:

forms of networks that use both approaches and even

- 21 -Statland, Norman and Winski, Donald

"Distributed Information Systems: Their Effect on Your

Company," Price Waterhouse Review, Vol.23, No. 1, 1978,

pp. 54-63.

This article examines the organizational and management

implications of the distributed processing environrr.ent

.

The authors point out that too often the general manager

has viewed the MIS department as an overhead cost which he/she wants to minimize, rather than seeing it as an

in-vestment to be maximized. The authors propose a distrib-uted processing scenario which plans systems development

and operations with the user and maintains a centralized

MIS department for promulgating standards and procedures.

Woods,

Larry D.

"Distributed Processing in Manufacturing," Datamation,

Vol. 23, October 1977, pp. 60-63.

"Addresses the potential for the loss of control and

the problems of maintaining corporate data bases in

light of the proliferation of minicomputers in a large

manufacturing company. Specifically, the environ,menr.

of the John Deere Company and its approach to solving

those problems are discussed." [from Quarterly

Biblio-graphy of Computers and Data Processing, Vol.7, no._4,

- 22

-LIST OF THE ARTICLES SURVEYED

(1) Becker, Hal B., "Preparing for Distributed Data Processing", Data

Comm User, January 1977, pp. 22-24.

(2) Becker, Hal B., "Six Steps to Network Analysis and Design", Data

Comm User, March 1977, pp. 30-31.

(3) Blair, James F. , "Distributed Information Systems", Telecoinaunications,

January 1974, pp. 39-40.

(4) Champine, G. A., "Six Approaches to Distributed Data Base Systems",

Datamation, May 19 77.

(5) Donaldson, Hamlsh, "A Case for Distributed Processing", Data Exchange,

July-August 1975, pp. 43-45.

(6) Edited, "Distributed Data Systems", EDP Analyzer, Vol. 14, June 1976,

pp. 1-13.

(7) Edited, "Distributed Systems and the End User", EDP Analyzer, Vol. 14,

No. 10, October 1976.

(8) Edited, "Distributed Computing and the Mini Computer", Canadian

Data-systems, July 19 74, pp. 38-39.

(9) Edited, "Distributed Minis Score Over One Large System at Equitable",

Data Comm User, March 1975, pp. 51-52.

(10) Edited, "Talking about Distributed Processing", Data Systems, February

1976, pp. 8-23.

(11) Edited, "Talking About Networks", Data Systems, March 1977, pp. 7-9.

(12) Edited, "Distributed Processing Is In, Whatever It Is", Datamation,

Vol. 22, December 1976, pp. 102-111.

(13) Emery, James

_C,

Computing," IFIP Proceedings,

i""'-'

pp. 945-55.

(14) Feidelman, Lawrence, "Its a Small World", Infosystems, Vol. 24,

April 1977, pp. 50-54.

(15) Fried, Louis, "Centralization: To Be or Not To Be", Infosystems,

January 1976.

(16) Giassr, George, "Distributed Data Prccass'.-.s: Prc-i^es 2r.d

Pit-falls", Proceedings of the IDC Conference on Distributed

23

-(17) Hannan, Jaiies and Fried, Louis, "Should You Decentralize," Computer

Decisions, Vol, 9, February 19 77, pp. ^0-42.

(18) Hunter, John J., "Distributing a Database", Computer Decisions,

Vol. 8, June 1976, pp. 36-40.

(19) Kelsch, August L., 'Dispersed and Distributed Data Processing," Journal

of Systems Management, Vol. 29, No. 3, March 1978, pp. 32-37.

(20) Kieder, Stephen P., "Once Again: Centralize or Decentralize",

Info-systems, December 1976.

(21) La Voie, Paul, "Distributed Computing, Systematically", Computer

Decisions, Vol. 9, March 1977, pp. 44-45.

(22) Luke, John W. , "Unravelling the Confusion of Distributed Data

Processing", Infosystems, December 1976.

(23) Lusa, John M. , "Distributed Computing: Alive and Well", Infosystems,

November 1976.

(24) Patrick, Robert L., "Decentralizing Hardware and Dispersing

Responsi-bility", Datamation, May 1976.

(25) Reynolds, Carl H., "Issues inCentralization", Datamation, March 1977.

(26) Ritchie, Robert 0., "Intelligent Terminals and Distributed

Process-ing", Computer Decisions, February 1975, pp. 36-42.

(27) Rockart, John F., Leventer, Joav S., and Bullen, Christine V,,

"Cen-tralization versus Decentralization of Information Systems:

A Preliminary Model for Decision-Making", CISR Report, Sloan

School of Management, MIT, Cambridge, Massachusetts

(28) Severino, Elizabeth F, "Database and Distributed Processing", Computer

Decisions, Vol. 9, M^rch 1977, pp. 40-42.

(29) Statland, Norman and Dor.ald Winski, "Distributed Information Systems:

Their Effect on Your Company," Price Waterhcuse Review, Vol. 23,

No. 1, 1978, pp. 54-63.

(30) Woods, Lariy D., "Distributed Processing in Manufacturing," Datamation,